3 The Remarkable Body Copyright 2017 Cengage Learning

A Cell (Simplified Diagram) Copyright © 2017 Cengage Learning. All Rights Reserved.

From DNA to Living Cells Copyright © 2017 Cengage Learning. All Rights Reserved.

Cells, Tissues, Organs, and Systems • Cells organized into tissues – Perform specialized tasks • Tissues grouped together to form organs • Organs work together as part of body systems Copyright © 2017 Cengage Learning. All Rights Reserved.

The Body Fluids and the Cardiovascular System • Body fluids – Supply energy, oxygen, nutrients, and water – Deliver fresh supplies and pick up wastes • Circulating fluids – Blood • Travels in arteries, veins, and capillaries • Plasma – Lymph • Travels in its own vessels Copyright © 2017 Cengage Learning. All Rights Reserved.

Blood Flow in the Cardiovascular System Copyright © 2017 Cengage Learning. All Rights Reserved.

How the Body Fluids Circulate Around Cells • Extracellular fluid • Intracellular fluid –

Lymph Vessels and the Bloodstream Copyright © 2017 Cengage Learning. All Rights Reserved.

The Hormonal and Nervous Systems • Hormones – Chemical messengers – Secreted and released directly into blood by glands – Stimulate organs to take action • Glands monitor conditions in the body – Pancreas • Insulin and glucagon Copyright © 2017 Cengage Learning. All Rights Reserved.

The Hormonal System Affects Nutrition • Some functions of hormones – Regulate the digestive system in response to meals or fasting – Inform the brain about the degree of body fatness – Help regulate hunger and appetite – Influence appetite changes during a woman’s menstrual cycle and in pregnancy – Regulate the body’s reaction to stress, suppressing hunger and digestion Copyright © 2017 Cengage Learning. All Rights Reserved.

How Does the Nervous System Interact with Nutrition? • Fight-or-flight reaction (stress response) – Neurotransmitters • Epinephrine and norepinephrine – Metabolism speeds up – Organ response • Eyes, heart, liver, and stomach – Heart disease Copyright © 2017 Cengage Learning. All Rights Reserved.

The Immune System • Tissues cooperate with each other to maintain defenses – Physical barriers • Antigen • Immune defenses – White blood cells • Phagocytes • Lymphocytes (T-cells and B-cells) Copyright © 2017 Cengage Learning. All Rights Reserved.

Inflammation • Response to cell injury or irritation – Increased white blood cells, redness, heat, pain, and swelling • Normal, healthy response • Problem with chronic inflammation – Dietary factors Copyright © 2017 Cengage Learning. All Rights Reserved.

The Digestive System • Five basic chemical tastes – Sweet, sour, bitter, salty, and umami • Other factors affect our experience of food flavor as well • Sweet, salty, and fatty foods – Almost universally desired – Can lead to drastic overeating of these substances Copyright © 2017 Cengage Learning. All Rights Reserved.

The Digestive System Copyright © 2017 Cengage Learning. All Rights Reserved.

The Mechanical Aspect of Digestion • Begins in the mouth – Chewing • Stomach and small intestine – Peristalsis – Chyme travels through pyloric valve • Large intestine • Digestion is virtually continuous – Sleep and exercise Copyright © 2017 Cengage Learning. All Rights Reserved.

Peristaltic Wave Passing Down the Esophagus and Beyond Copyright © 2017 Cengage Learning. All

The Muscular Stomach Copyright © 2017 Cengage Learning. All Rights Reserved.

The Chemical Aspect of Digestion • Digestive juices – Salivary glands, stomach, pancreas, liver, and small intestine • Saliva functions in the mouth – Breaks down starches and fat – Maintains tooth health • Stomach – Gastric juice includes hydrochloric acid • Initiates protein digestion Copyright © 2017 Cengage Learning. All Rights Reserved.

p. H Values of Digestive Juice and Other Common Fluids Copyright © 2017 Cengage

The Chemical Aspect of Digestion (cont’d. ) • Intestine – Bile – Pancreatic juice neutralizes stomach acid – Digestive enzymes in intestinal wall – Water, fiber, and some minerals remain • Microbes in the digestive tract – Ferment many indigestible fibers – Break down undigested protein, bile components, and drugs Copyright © 2017 Cengage Learning. All Rights Reserved.

If “I Am What I Eat”, Then How Does A Peanut Butter Sandwich Become “Me”? • Within 24 to 48 hours – Body digests and absorbs 90% of carbohydrate, fat, and protein in a meal • Mouth – Food is crushed, mashed, and mixed with saliva – Carbohydrate digestion begins – Swallowing • Peristaltic waves Copyright © 2017 Cengage Learning. All Rights Reserved.

Digestion of a Peanut Butter Sandwich (cont’d. ) • Stomach – Gastric juice mixes with food • Acid unwinds proteins – Chyme • Small intestine – Bile from the liver – Enzymes from pancreas • Large intestine – Fiber fragments, fluid, and some minerals absorbed Copyright © 2017 Cengage Learning. All Rights Reserved.

Details of the Small Intestinal Lining Copyright © 2017 Cengage Learning. All Rights Reserved.

Nutrient Transport • Lymph vessels – Products of fat digestion – Fat-soluble vitamins • Blood vessels – Products of carbohydrate and protein digestion – Most vitamins – Minerals • Nourishment of digestive tract Copyright © 2017 Cengage Learning. All Rights Reserved.

Normal Swallowing and Choking Copyright © 2017 Cengage Learning. All Rights Reserved.

The Excretory System • Organs involved in waste removal – Lungs, liver, and kidneys • Kidneys – Waste materials are dissolved in water – Working units – nephrons – Urine stored in bladder • Sodium helps regulate blood pressure – Excreted or retained by kidneys • Importance of water supply Copyright © 2017 Cengage Learning. All Rights Reserved.

Storage Systems • Eating intervals: four to six hours • Major storage sites – Liver – carbohydrates • Glycogen – Muscles – carbohydrates • Glycogen – Fat cells – fat and fat-related substances • Body stores exist for many other nutrients Copyright © 2017 Cengage Learning. All Rights Reserved.

Does Moderate Alcohol Use Benefit Health? • Some studies suggest reduced risk of heart attacks, strokes, and diabetes – Associated with moderate drinking • Light or moderate drinking may be associated with mental acuity in aging – Higher intakes not associated with benefits of any kind • Health benefits of red wine – Science is mixed Copyright © 2017 Cengage Learning. All Rights Reserved.

What is Alcohol? • Names end in –ol • Act as lipid solvents •

What is a “Drink”? • Percent of alcohol differs among beverages – Proof: twice

Drinking Patterns • Moderate drinking – Amounts different for women and men • Problem drinkers and alcoholism – Irrational and dangerous behaviors • Heavy episodic (binge) drinking – Defined – Harmful effects Copyright © 2017 Cengage Learning. All Rights Reserved.

Effects of Rising Blood Alcohol Levels on the Brain Copyright © 2017 Cengage Learning.

Alcohol Doses and Average Blood Level Percentages in Men and Women Copyright © 2017

Blood Alcohol and Traffic Accidents Copyright © 2017 Cengage Learning. All Rights Reserved.

Alcohol Breakdown Copyright © 2017 Cengage Learning. All Rights Reserved.

Alcohol Affects the Liver • Alcohol metabolism generates damaging free radicals – Diseases and organ damage • Fatty liver • Liver fibrosis – Cirrhosis Copyright © 2017 Cengage Learning. All Rights Reserved.

Alcohol’s Effects on Nutrition • Causes disturbances in nutrition • All discretionary calories • Fattening power of alcohol – “Beer belly” • Effects on vitamins – Malnutrition – Wernicke-Korsakoff syndrome – Folate Copyright © 2017 Cengage Learning. All Rights Reserved.